Heat-assisted magnetic recording (HAMR) is a technology that magnetically records data on high-stability media using laser thermal assistance to first heat the material. HAMR takes advantage of high-stability magnetic compounds such as iron platinum alloy. These materials can store single bits in a much smaller area without being limited by the same superparamagnetic effect that limits the current technology used in hard disk storage.
High-density digital recording requires small grain size hence increased susceptibility to thermally-induced paramagnetism and decay of written information. Increasing the ferromagnetic anisotropy of the medium may reduce the paramagnetic phenomena but may require excessive write fields.
Heat-Assisted Magnetic Recording (HAMR) may resolve the writeability versus longevity dilemma by using a beam from a laser diode to raise the temperature of the medium in the vicinity of a written transition to near the Curie point, allowing the writer to switch the medium.